Subtract 12/21 from 4/42
4/42 - 12/21 is -10/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 21 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 42 × 1 = 42,
4/42 = 4 × 1/42 × 1 = 4/42 - Likewise, for the 2nd fraction, since 21 × 2 = 42,
12/21 = 12 × 2/21 × 2 = 24/42 - Subtract the two like fractions:
4/42 - 24/42 = 4 - 24/42 = -20/42 - After reducing the fraction, the answer is -10/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 8/42-12/21 4/42-24/21 4/84-12/21 4/42-12/42 12/42-12/21 4/42-36/21 4/42-12/63 20/42-12/21 4/42-60/21 28/42-12/21 4/42-84/21